What should I do if there’s an emergency, like a fire drill during the AP Chinese or AP Japanese Exam?

In an emergency, the primary concern should be the safety of everyone present. If necessary, evacuate everyone immediately.
If there's enough time, refer to the "Breaks and Emergency Stops" section of the AP Chinese and AP Japanese Exams: Setup and Administration Guide (available at collegeboard.org/apcj-examadmin) for instructions on stopping the exams.
Lock the testing room door after everyone has exited.